We treated three cases of bone tumors-giant cell tumor, chondroblastoma and malignant fibrous histiocytoma-with a custom-made prosthetic replacement. The patients were followed from 10 months to 18 months, postoperatively. The results of these study are as follows: 1. Satisfactory anatomic restoration 2. Early ambulation 3. Good function 4. Biomechanically sound reconstruction